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Posted by johnshannon | May 09, 2021 @ 05:10 PM | 2,400 Views
This is the long-form of my journey of the K&B 15RS (aka Wart, aka Racing Schnürle). First, I must acknowledge my friends without whom this project would have been impossible. Luke Roy (of Rattler fame) provided invaluable data. He has an original barstock case and sleeve from the prototype phase plus one of the investment case cases that came after the 15RS. This provided the details of the sleeve porting and case transfer shapes. Luke also reverse-engineered the stroke based on the cylinder bore. Bill Hughes contributed detail photos (aka Mug Shots) of Glenn Lee’s engine used at the 1964 F2A WCs. Additionally, he provided certain critical dimensions and important information like the engine used a K&B 15R rod. Darron Black (aka “Boy Wonder” because he reminds Dub and me too much of ourselves at his age) is a friend of Dub and mine that provided invaluable support for me learning Autodesk Fusion 360 and identifying Shapeways as a source of 3D printing directly in aluminum. Bill Wisniewski, of course, is the designer of the of the K&B 15RS and provided critical information about its design and development in personal conversations. And last, but not least, is Dub Jett, my life-long flying partner and friend who supported my efforts with his excellent advice. As the Beatles’ song says “I get by with a little help from my friends”!

The precursor of the K&B 15RS is the developmental prototype engine by Bill Wisniewski used to incorporate schnürle porting into...Continue Reading
Posted by johnshannon | Mar 25, 2015 @ 08:09 PM | 6,521 Views
First, the name DJS stands for Dub Jett and John Shannon, with the “J” being shared. John and Dub have a very long and wonderful association as friends and model airplane flyers. This association began when they were both teenagers in 1959 and continues today.

The DJS 049 was ahead of its time, being designed in 1976.

The DJS 049 has its genesis as a project to provide Dub with a platform to achieve excellence in his favorite event of 1/2A Speed. John won 1/2A Speed at the 1973 AMA Nationals using a Cox Tee Dee 049 with a homemade chromed 3-port cylinder with a tuned pipe. This is a very good combination, however at RPMs over 30K the rod ball separates from the piston. The DJS 049 is essentially a 0.551 scale model of the DJS 29 with the exception of the bore and stroke. Originally, the bore and stroke were based on the DJS 29 at 0.412 and 0.370 inches. After the design was completed this was changed to 0.406 and 0.386 inches to be the same as the Cox Tee Dee 049 that was very familiar and competitive. Maybe DJS confidence was not as high as it could have been as this provided a path to using the Cox piston and rod assembly, if necessary. It was not necessary!

Dub developed an original design tuned pipe with the correct tuning RPM and volumetric characteristics. His first design was perfect. The real success of this project is not just Dub’s pipe design, but its fabrication. Dub has many things at which he is a wizard. His wizardry is never any greater than aluminum...Continue Reading
Posted by johnshannon | Mar 24, 2015 @ 10:41 PM | 6,769 Views
Ok. I guess I have a blog here. This is a first shot to see if it works!

Johnny